IEEE Approved Draft Standard for a Mixed-Signal Test Bus

The testability structure for digital c 1 ircuits described in IEEE Std 1149.1 has been extended to provide similar facilities for mixed-signal circuits. The architecture is described, together with the means of control of and access to, both analog and digital test data. Sample implementation and application details (which are not part of the standard) are included for illustration. Also, extensions to the standard BSDL are defined that allow description of key component-specific aspects of such testability features.